Contact bus bar

ABSTRACT

A contact bus bar utilized as a common stationary contact element cooperating with a plurality of movable contact elements comprises an elongated body and a plurality of contacting chips disposed on the body lengthwise thereof at regular intervals in correspondence with the respective movable contact elements. Each of said chips is spot-welded to said body at positions apart from the contact point of the corresponding movable contact element.

United States Patent [72] Inventor Shinichi Murakami [56] References Cited HIInImfl -S J pan UNITED STATES PATENTS 22 2 2,949,803 8/1960 Leslie ..200/166 1 x [2 1 2,959,693 11/1960 Meyer ..200/166(. 1 x [451 meme! 1971 2 060 784 10/1962 H0" ..200/l66(. 1 x [73] Assignee Nippon Gakki Selzo Kabushiki Kaisha l-lamalnatsu-shi, Japan Primary Examinerll. 0. Jones [32] Priority Sept. 13, 1968 Attorney-George B. Oujevolk [33] Japan [31] Utility Model 79153/68 v ABSTRACT: A contact bus bar utilized as a common stationary contact element cooperating with a plurality of movable [54] E contact elements comprises an elongated body and a plurality w g of contacting chips disposed on the body lengthwise thereof at [52] US. 200/166 regular intervals in correspondence with the'respective mova- [51] Int. H0lh l/06 ble contact elements. Each of said chips is spot-welded to, said [50] Field of Search 200/ 166. 1', body at positions apart from the contact point of the cor 166 (B8),(l66C); 84/l.l l, 1.17, 423

responding movable contact clement.

PATENTED MAR SISTI 3,569,654

FIG. 3

A q VW W INVEN'I'OR.

1 CONTACT nus BAR BACKGROUND OF THE INVENTION The present invention relates to a contact bus bar used as a common stationary contact element on the output side of keying switches of a musical instrument, for example, an electronic organ, said bus bar cooperating with a plurality of movable contact elements on the inputside of said keying switches.

An electronic musical instrument generally involves a plurality of keying switches having a common stationary contact element and a plurality of movable contact elements each cooperating with said stationary. contact'element so that a tone signal corresponding to a predetermined pitch is produced by contacting any movable contact element with said common stationary contact element.

The prior art contact bus bar utilized as a common stationary contact clement consists of a long base of nickel-silver or copper-nickel and a long rounded bar member of gold-silver alloy disposed on said base along its length. The bar member is seam-welded to said base. Nevertheless, the bar member is extremely expensive due to use of gold-silver alloy. Furthermore, the contact surface of said member is unavoidably roughened by the seam-welding, leading to poor contact between the stationary and movable contact elements.

SUMMARY OF THE INVENTION The object of this invention is to provide a contact bus bar so improved as to cause movable contact elements surely and conveniently to contact a stationary contact element with a plurality of contact chips spot-welded to a body of said bus bar in correspondence with the respective movable contact elements. Said chips are arranged on said body at certain intervals, reducing the cost of a stationary contact element as a whole.

In an aspect of this invention, the contact bus bar utilized as a common stationary contact element cooperating with a plurality of movable contact elements comprises a long body, and a plurality of contacting chips disposed on said body lengthwise thereof at certain intervals in correspondence with the respective movable contact elements and spot-welded to said body at positions apart from the contact point of the corresponding movable contact element.

This invention will be clearly understood from the following description with reference to the accompanying drawing.

BRIEF EXPLANATION OF TI-IEDRAWING FIG. 1 is a perspective view of switching mechanisms involving a contact bus bar embodying this invention;

FIG. 2 is an enlarged front view of said contact bus bar; and FIG. 3 is a cross-sectional view of said contact bus bar.

DETAILED DESCRlPTlON or AN EMBODIMENT element I. Said stationary contact element 1 consists of a contact bus bar of this invention. Said contact bus bar, as shown in FIGS. 2 and 3,.comprises a long body 3 of conductive material, such as nickel-silver *or copper-nickel, and a plurality of contacting chips 4 of a precious metal, such as a gold-silver alloy. Said chips 4 are arranged on said body 3 lengthwise thereof at regular intervals in correspondence with the respective movable contact elements 2, and spot-welded to said body 3 at positions, for example, at the end portions of the chip apart from the contact point of the corresponding movable contact element 2. I

Said long body 3 preferably comprises a flat head 3a, shoulders 3b sloping from thehead downwardly, and a flat bottom 3c. On the surface of the flat head3a are disposed the abovementioned chips 4. Each of said chips 4 is preferabl vertically arched n a manner to have its mid e portion raise above the surface of the flat head 30, so thateach of the movable contact elements 2 contacts said middleportion with the arcuate top of said chip elastically depressed, This elasticity of the middle portion serves to alleviate the impact caused by contacting the movable contact element with the stationary contact element,

so that the mechanical noises by collision and electrical noises by chattering are reduced.

Said chip 4 is practically so designed as to be 5 to 6 mm. long and 0.15 mm. in diameter and consists of a gold-silver alloy in which the gold accounts for percent by weight and the silver 20 percent by weight. Furthermore, said chip 4 is vertically arched in a manner to have its middle portion raised 0.05 to 0.1 mm. above the surface of the flat head 3a. Said chip 4 is spaced 7 to 8 mm. from the adjacent one. The body 3 is 1.6 mm. wide and 1.05 mm. high, its flat head 3a being 0.3 to 0.4 mm. wide.

Accordingly, the contact bus bar of this invention can cause the movable contact elements surely and conveniently to contact the stationary contact element, since the contact chips are spot-welded at positions apart from the contact point of the corresponding movable contact elements so as to avoid the middle contacting portions of said chips, and the middle contacting portions are vertically arcuated. And the chips are arranged on the body of bus bar at certain intervals, and the cost of the stationary contact element is considerably reduced.

I claim:

l. A contact bus bar utilized as a common stationary contact element cooperating with a plurality of movable contact elements, comprising a long body, and a plurality of contacting chips disposed on said body lengthwise thereof at certain intervals in correspondence with the respective movable contact elements and spot-welded to said body at positions apart from the contact point of the corresponding movable contact element.

2 A contact bus bar claimed are vertically arched.

3. A contact bus bar claimed in claim 1 in which said body is made of nickel-silver and said chips are made of gold-silver alloy. H

4. A contact bus bar claimed in claim 1 in which said body is made of copper-nickel and said chips are made of gold-silver alloy. Y I

in claim 1 in which said chips 

1. A contact bus bar utilized as a common stationary contact element cooperating with a plurality of movable contact elements, comprising a long body, and a plurality of contacting chips disposed on said body lengthwise thereof at certain intervals in correspondence with the respective movable contact elements and spot-welded to said body at positions apart from the contact point of the corresponding movable contact element.
 2. A contact bus bar claimed in claim 1 in which said chips are vertically arched.
 3. A contact bus bar claimed in claim 1 in which said body is made of nickel-silver and said chips are made of gold-silver alloy.
 4. A contact bus bar claimed in claim 1 in which said body is made of copper-nickel and said chips are made of gold-silver alloy. 